Portable physician&#39;s and dentist&#39;s light and switch therefor



Dec. 29, 1931. E. VAJDA 1,838,202

PORTABLE PHYSIC-IANS AND DENTISTS LIGHT AND SWITCH THEREFOR Filed Nov, 2, 1928 Fly 2 31a/mute@ Elize/g //'aa Patented Dec. 29, 1931 n UNITED STATES PATENT OFFICE EMERY VAJDA, 0F CLEVELAND, OHIO, AssIGNoR, BY MESNE ASSIGNMENTS, T0

WM. F. WE'HRLE PORTABLE PHYSICIANS AND DENTISTS LIGHT THEREFOR Application. filed November 2, 1928.

My inventionrelates to low voltage electrical appliances adapted for being operated by connection with outlets of ordinary electric light circuits of 110-120 volts, for example.

More particularly my invention relates to improvements in the low voltage lights for physicians and dentists set forth in my application for patent, Serial No. 264,223, iled March 23, 1928, and in my application for patent, Serial No. 290,454, filed July 5, 1928.

in this electrical appliance, as well as other low voltage appliances, it is essential that the voltage for the appliance be reduced from the impressed voltage of the lighting circuit, to the required .voltage for the appliance.

@n the other hand in the case of lights for physicians and dentists, from the standpoint ot safety for patients, and for ease of operation, it is undesirable that any substantial quantity of heat be given off by the light or by the conductors immediately adjacent the light handle.

Moreover, a conveniently located switch is essential for the proper use of such lights by physicians and dentists.

Accordingly the objects of the present improvements include the provision of a low voltage light, arranged with resistance conductors, plain conductors, a connector between the conductors, a switch, and a connector plug, in a novel manner whereby the. connector plug may be inserted into the outlet of an ordinary electric light circuit, and the desired low voltage will be impressed upon the light, and the undesired giving on of heat near the light will be substantially eliminated. Y

Further objects of the improvements include the provision of va compact and easily assembled telescopic switch adapted for embodiment in aI handle which also mounts the light socket.

These and ancillary objects are attained in the present improvements, as will be hereinafter set forth in detail and claimed.

A preferred embodiment of the invention is illustrated in the accompanying drawings forming part hereof, in which Serial No. 316,773.

Figure 1 is an elevational lview with por- 'tionsbroken away of the improved light for physicians and dentists;

lig. 2, an enlarged longitudinal sectional View of the handle illustrating the improved 5:, telescopic switch; and

Fig. 3, a perspective View illustrating parts gif: ghe handle and switch about to be assem- Similar numerals refer to similar parts through the drawings. y

The improved light 'for physicians,Y dentists, and the like is indicated generally at 10, and includes the improved tubular handle 11 of relatively small diameter, and 65 preferably made of insulating material, and in one end of which is mounted a lamp socket 12.

The socket is adapted to have `:screwed therein, the base 16a of anelongated electric 70 lamp 16, the bulb 17 of which is preferably in the form of a cylindric tube of small diameter and having a closed outer end 18 and joined at its other end with the base 16a in the usual manner, and the bulb being evacuated, and there being a filament 19 located vwithin the bulb adjacent the outer end 18 thereof, one terminal of the iilament being connected in a usual manner with the screw cup. 162) of the base, and the other terminal 0 of the filament being connected with the center contact of the base, there being insulating material between the centercontact 160 and the screw cup 1Gb, in the usual inanner, and the bulb 17 is preferably opaque 85 throughout the greater portion of its length.

The lamp is thus of usual construction, and

`in order to enable the provision of the relatively small diameter required for the elongated tube bulb 17', and as a safety measure, it o is desired that the filament 19 be lighted by a current of relatively low voltage which may be for example 10 volts in lights for physicians use, or 6 volts in lights for dentists use.

On the other hand it is desirable that the lamp be adapted for operation by connection as by means of a plug connector 2O with an ordinary electric light circuit of 11G-120 100 volts, and that a switch be provided for controlling the illumination of the lamp.

It is moreover desirable that the potential difference between the terminals of the switch be as low as possible.

Moreover as aforesaid it is desirable that substantially no heat be given off at or near the light.

Accordingly a resistance cable 22 is utilized to connect the A plug' connector'20 withone side of a connector 21, and 'this resistance cable is itself covered with asbestos or other suitablev heatinsulating material, and for a l() volt light, has a resistance of substantially 48 ohms per foot and is 7 feet in length. 'F or lights of other voltages the length or resistance per foot ofthe cable 22 is suitably varied. Y v

Y The other side of the connector 2l is connected by an ordinary cablev 23 which4 may be 3 feet long, through the improved telescopic switch 24 with the socket in the tubular handle 1l in a novel manner. f

The improved switch 24 is operatively mounted within the tubular handle 11,'and includes a longitudinal-mounting member 25 preferably made of insulating material, which is adapted to be inserted into the Vhandle through the lower cable end opening 26 thereof.

The lamp socket l2, preferably includes "one terminal 27, which is in the form of an internally threaded cup made of conducting material, and into which the externally threaded base 16a of the lamp 16, is arranged Yto be screwed. 1

The bottom wall 29 of the cup is provided with a central aperture therein which registers with the opening in a wedge tapered .tubular switch terminal 30, which is prefer- 'ably formed integral with the cup 27.

The other terminal of the lamp socket, for Y connecting with the lamp base center'contacts 160, is preferably in the form of an enlarged head 31 at the outer end'of a conductor rod '32, which longitudinallyr extends through a lgore axially'located in the mountingmemer 25.

The socket end 33 of the mounting member 25, is of reduced diameter to iit within the registering apertures in the switchy terminal 30 and the socket bottom wall 29, `and to extend beyond the socket side of the bottom wall 29, so that the socket terminal Y .head 3l will be properly insulated from the -socket cup terminal 27. v

The other switch terminal is provided by longitudinally extending conducting strip `34, l, preferably curved about the cylindric middle portion'35 of the mounting mem- Yber 25. n

As aforesaid, the mounting member 25 is preferably made of insulating material, fwherebytheconductor rod 32 is insulated y from the conducting strip 34.

is slidably inserted over and fits the conducting strip 34, is arranged for movement towards the tubular terminal 30for telescopilcally electrically vconnecting the same with the conducting strip 34, and for movement away from the tubular terminal 30 for breaking the electrical connection.

The wedge tapered tubular terminal 3() is arranged to telescopicallyv lit in the adjacent beveled end 37 of the sleeve 36.

Y The conducting strip 34 ssecured to the mounting member 25 by means of a screw 3S, AVwhich also serves to connect the conducting strip vwith one of the conductors 39 of the cable 23.

A screw 40 serves to secure the conductor rod 32 within the mounting member 25, and to connect the same with the other conductor 4l of the cable 23.

The mounting member 25 and attached Vparts are secured within the tubular handle 1l s Aan inwardly projected flange 45, which serves to secure a spiral guard 46 for the cable 23.

Means for moving the ring or sleeve contact member 36 is provided by a screw 47 which is screwed into the contact member 36 through a longitudinally extending slot 48 in the tubularv handle ll, and a knob 49 preferably of insulating material be cemented upon the outer end of the screw 47.

By` these means a very easily assembled socket and switchv structure are provided for 'the purpose herein set forth, the novel switch structure being certain and sure in its operation at all times.

It is obviousthat thisimproved telescopic switch structure may be adapted for other purposes, it is not intended to limit its use Ato that particularly set forth herein.

I claim: Y

l. An electrical switch including a handle,

a pairfof lamp terminals mounted in the handle, an insulation member located in the handle and'extending between the terminals, one of the terminals being adapted for connection with a conductor, a conducting strip mounted upon the insulation member and adapted for connection with another conductor, a contact member movably mounted inthe handle and slidably contacting` With the strip, the contact member being movable into engagement With 5 the other terminal for connecting the strip With the other terminal by movement in one direction and for breaking the connection by a movement in the opposite direction.

2. An electrica-l instrument including a handle7 a socket in the handle adapted for mountingan electrical appliance of relatively low voltage, the socket including` a pair of lamp terminals, an insulation member located in the handle and extending between the terminals, one of the socket terminals being adapted for connecti on with a conductor, the other socket terminal being tapered, a conducting strip mounted upon the insulation member and adapted for connection With another conductor, a contact member movably mounted in the handle and slidably contacting with the strip, the movable Contact member being movable into Wedge enga-gement with the tapered terminal for connecting the strip With the taperedV terminal by a movement in one direction and for breaking the connection by a movement in the opposite direction.

n In testimony that I claim the above, I have 00 hereunto subscribed my name.

EMERY VAJDA. 

